Columbia-Presbyterian Medical Center is developing an information network that will allow appropriate users to access: 1) clinical, scholarly, and administrative information; 2) a comprehensive patient database which will facilitate clinical research; and 3) computer resources for basic research and communication between geographically dispersed colleagues. Our long range goal is to conveniently deliver information to the location where and at the time when it is needed. The improved information flow should contribute to savings of time and effort and an increase in the quality of patient care, research, and education at our institution. These objectives will be accomplished vis: 1) the installation of a network that will connect the health sciences center, a community hospital two miles distant, a dispersed ambulatory care network, and a research park; 2) the use of affordable workstation hardware and software that will allow users to access information without interrupting the task at hand; and 3) the construction of a hospital information system in modules using applications developed by institutional personnel and available products. Novel aspects of our proposal are the delivery of medical knowledge via a data driven mechanism for evoking computer decision logic and the construction of knowledge bases in a format suitable for sharing with other institutions.